JP4895361B2 - Electrolyte-catalyst composite electrode for dye-sensitized solar cell, method for producing the same, and dye-sensitized solar cell provided with the same - Google Patents

Description

  The present invention relates to a catalyst electrode of a dye-sensitized solar cell and a dye-sensitized solar cell including the same.

In recent years, dye-sensitized solar cells in which a semiconductor layer is loaded with a sensitizing dye that absorbs a visible light region have been studied. This dye-sensitized solar cell is expected to be put to practical use because of the advantages that the material used is inexpensive and that it can be manufactured by a relatively simple process.
In the dye-sensitized solar cell, electrons are injected from the sensitizing dye excited by absorbing visible light into the semiconductor electrode, and current is taken out through the current collector. On the other hand, the oxidized form of the sensitizing dye is reduced and regenerated by a redox pair in the electrolyte. The oxidized redox pair is reduced on the surface of the catalyst electrode placed opposite to the semiconductor electrode, and the cycle goes around.
Known catalyst electrodes conventionally used in dye-sensitized solar cells include those obtained by applying chloroplatinic acid on an electrode substrate and heat-treating it, and platinum catalyst electrodes obtained by depositing platinum. In this catalyst electrode, oxidation-reduction pair in the electrolyte (e.g., I ₃ ^over / I ^-, etc.) an oxidant reduction reaction for reducing the reduction of the (I ₃ ^{- -} The I reduction reaction reduced to) promptly What has the electrode characteristic which can be advanced is calculated | required.

  However, in consideration of practical use, electrolytes have been studied to increase viscosity and gelation. However, in dye-sensitized solar cells equipped with platinum catalyst electrodes as described above, oxidation occurs as the electrolyte increases in viscosity. The diffusion of iodine, which is a reducing pair, is a rate-limiting process of the electron transfer reaction in the solar cell, and there is a problem that the solar cell characteristics are deteriorated. For this reason, in order to rapidly proceed the iodine reduction reaction on the catalyst electrode surface, it was necessary to increase the surface area of the platinum surface or the electrode substrate coated with platinum, or to increase the platinum film thickness. As a result, there has been a problem that the required current value cannot be obtained with an increase in material cost accompanying an increase in the amount of platinum used and an increase in the surface area of the substrate.

Patent Document 1 discloses a dye-sensitized photovoltaic cell using a back electrode (catalyst electrode) formed of a porous layer of a conductive material, that is, a dye-sensitized solar cell. The back electrode in the patent is described as having an increased surface area due to its porosity, resulting in high catalytic efficiency with respect to electron exchange with the electrolyte.
Patent Document 2 exemplifies a conductive organic polymer, that is, a conductive polymer, together with conductive ceramic particles, as a kind of conductive material forming the porous layer. It is described that these conductive particles have catalytic deposition of metal powder, graphite powder, carbon black, and platinum group metals as options, and then are dispersed on the back electrode. That is, the conductive polymer particles are used as a carrier for applying a catalyst. Among these, it is described that the combination of graphite powder and carbon black has excellent corrosion resistance and electrocatalytic action on redox couples. Further, it is described that the reason for having an excellent catalytic action is due to the very large surface area of carbon black. Further, it is described that an adhesive is required to agglomerate and fix these powder powders, and that the adhesive can be suitably used by sintering titanium dioxide.

  However, the catalyst on the surface of the carrier cannot participate in the electrode reaction unless it contacts the conduction path of the redox couple contained in the electrolyte. Therefore, when a highly viscous or gelled electrolyte is used, the method for producing a catalyst electrode in Patent Document 1 does not penetrate to the deep part of the porous catalyst layer. It cannot contribute to the electrode reaction, and the usage rate of platinum is reduced. As a result, there arises a problem that the desired solar cell characteristics cannot be obtained.

Furthermore, when the carrier carrying the catalyst is fixed using an adhesive, the platinum catalyst in the bonded portion of the carrier surface does not come into contact with the electrolyte at all, which causes a further decrease in the platinum usage rate. there were. In addition, precious metals such as platinum have not solved the cost problem at all. In addition, when the metal is deposited as a catalyst, the I ⁻ / I ₃ ⁻ system, which has the same problem of lowering the usage rate and has excellent performance as a current redox couple, is originally iodine. Corrosion due to is inevitable. On the other hand, graphite and carbon black exemplified as suitable catalytic deposits have high durability against corrosive redox couples such as iodine, but the catalytic action itself is significantly inferior to platinum. The required solar cell characteristics have not been obtained.

  In addition, when titanium dioxide exemplified as a suitable adhesive is used, in order to obtain high conductivity, baking is required for the bonding step, which is very disadvantageous in terms of manufacturing process and manufacturing cost. At the same time, plastics and films cannot be used as electrode substrates for weight reduction and flexibility.

In general, the filling of the electrolyte solution into the solar battery cell is performed using the capillary phenomenon after the assembly of the cell. However, in order to increase the durability, a high viscosity or a ionic liquid electrolyte or a gel electrolyte is used. In the case of using a quasi-solidified electrolyte, uniform and rapid filling of the electrolyte is impossible. Furthermore, even when the above-mentioned catalyst electrode or porous semiconductor electrode with an enlarged surface area is used, it is difficult to fill the electrolyte deep in the electrode by capillary action, and the required solar cell characteristics can be obtained. There is no problem.
Various techniques have been proposed, but there is a need for a dye-sensitized solar cell that can be produced with a lower manufacturing cost and process and that exhibits excellent battery characteristics even when a high-viscosity electrolyte is used.

Japanese National Patent Publication No. 11-514787

In view of the above circumstances, the present invention is an electrolyte-catalyst composite electrode for a dye-sensitized solar cell, which can be produced by an inexpensive material and a simple manufacturing method, and even when a high-viscosity electrolyte is used. It is an object of the present invention to provide an electrolyte-catalyst composite electrode having excellent electrode characteristics that can reduce the oxidized form of the redox couple contained in the electrolyte quickly.
Another object of the present invention is to provide a method for producing an electrode-catalyst composite electrode for a dye-sensitized solar cell by using an inexpensive material with good operability and excellent electrode characteristics with low energy. Is to provide.
Another object of the present invention is to provide a dye-sensitized solar cell comprising the above electrolyte-catalyst composite electrode and having excellent photoelectric conversion efficiency.

As a result of intensive studies to solve the above-described problems, the present inventors have found that an electrolyte containing a chemical species that becomes a redox pair, and conductive fibers or particles in an electrolyte-catalyst composite electrode for a dye-sensitized solar cell. In addition, even when an electrode composed of a conductive polymer and / or a catalyst substance uses a high-viscosity electrolyte, the utilization rate of the catalyst is high, and the oxidized form of the redox couple contained in the electrolyte can be quickly obtained. It has been found that an excellent electrolyte-catalyst composite electrode that can be reduced is obtained.
The inventors of the present invention also provide an electrolyte-catalyst composite electrode having more excellent electrode characteristics by forming a three-dimensional network structure by electrically connecting the conductive fibers or particles to each other or being in contact with each other. I found out that
The inventors of the present invention also provide an electrolyte-catalyst composite electrode having more excellent electrode characteristics by contacting a catalyst substance on a conductive fiber or particle surface and contacting a conduction path of a redox pair contained in the electrolyte. I found out that
The inventors of the present invention also provide a three-dimensional network structure in which a catalytic substance is supported on the surface of conductive fibers or particles, and is brought into contact with or fixed to each other via the catalytic substance to electrically conduct the structure. It has been found that an electrolyte-catalyst composite electrode having excellent electrode characteristics is obtained.
Furthermore, the inventors of the present invention have a three-dimensional network structure in which a conductive polymer is formed on the surface of conductive fibers or particles, and is brought into electrical contact with each other through the conductive polymer so as to be electrically connected. And it discovered that it became an electrolyte-catalyst composite electrode excellent in electrode characteristics by carrying | supporting a catalyst substance on the surface of this conductive polymer.

  Accordingly, the present invention provides an electrode disposed opposite to a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, the electrolyte containing a chemical species that becomes a redox pair, and conductive fibers or particles. An electrolyte-catalyst composite electrode for a dye-sensitized solar cell, which is composed of a conductive polymer and / or a catalyst substance.

  The present invention also provides an electrolyte for a dye-sensitized solar cell, wherein the conductive fibers or particles are in contact with each other or fixed to be electrically connected to form a three-dimensional network structure. It is a catalyst composite electrode.

The present invention also provides an electrolyte-catalyst composite electrode, wherein the catalyst substance is supported on the surface of conductive fibers or particles and is in contact with a conduction path of a redox pair contained in the electrolyte.

Furthermore, the present invention is characterized in that the three-dimensional network structure in which a catalytic substance is supported on the surface of the conductive fibers or particles is electrically connected to or in contact with each other via the catalytic substance. It is an electrolyte-catalyst composite electrode of description.

  Examples of the catalyst material include conductive polymers. Examples of the monomer that forms the conductive polymer include aromatic amine compounds represented by the following general formula (1) or (2).

（式（１）又は（２）中、Ｒ_１及びＲ_６はそれぞれ独立に水素原子、メチル基又はエチル基を示し、Ｒ_２〜Ｒ_５及びＲ_７〜Ｒ_１０はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、炭素原子数６〜１２のアラルキル基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、アミド基、ヒドロキシル基、チオール基、カルボキシル基、スルホ基、又はホスホニウム基を示し、式（１）中、Ｒ_２とＲ_３、又はＲ_４とＲ_５はそれぞれ連結して環を形成していてもよく、式（２）中、Ｒ_８とＲ_９、又はＲ_９とＲ_１０はそれぞれ連結して環を形成していてもよい。）
該芳香族アミン化合物として、アニリン、アニシジンなどが挙げられる。

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. An alkyl group or an alkoxy group having 1 to 8 atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, a halogen group, a nitro group, an amino group, an amide group, A hydroxyl group, a thiol group, a carboxyl group, a sulfo group, or a phosphonium group is shown, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ may be linked to form a ring, In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)
Examples of the aromatic amine compound include aniline and anisidine.

  As another monomer that forms the conductive polymer, a thiophene compound represented by the following general formula (3) can be given.

（式（３）中、Ｒ_１１、Ｒ_１２はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ_１１とＲ_１２は連結して環を形成していてもよい。）
該チオフェン化合物として、チオフェン、３，４−エチレンジオキシチオフェンなどが挙げられる。

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. , A nitro group, an amino group, a carboxyl group, a sulfo group, or a phosphonium group, R ₁₁ and R ₁₂ may be linked to form a ring.)
Examples of the thiophene compound include thiophene and 3,4-ethylenedioxythiophene.

  As another monomer for forming the conductive polymer, a pyrrole compound represented by the following general formula (4) can be given.

（式（４）中、Ｒ_１３、Ｒ_１４はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ_１１とＲ_１２は連結して環を形成していてもよい。）
該ピロール化合物として、ピロール、オクチルピロールなどが挙げられる。

(In Formula (4), R <_13> , R <_14> is respectively independently a hydrogen atom, a C1-C8 alkyl group or an alkoxy group, a C6-C12 aryl group, a cyano group, a thiocyano group, and a halogen group. , A nitro group, an amino group, a carboxyl group, a sulfo group, or a phosphonium group, R ₁₁ and R ₁₂ may be linked to form a ring.)
Examples of the pyrrole compound include pyrrole and octylpyrrole.

Furthermore, the present invention also provides that the three-dimensional network structure in which a conductive polymer is formed on the surface of the conductive fibers or particles is in contact with or fixed to each other through the conductive polymer to be electrically connected. And an electrolyte-catalyst composite electrode, wherein a catalyst substance is supported on the surface of the conductive polymer.
Examples of the catalyst material at this time include a noble metal or an alloy thereof, and more specifically, platinum or an alloy thereof.

  Examples of the monomer that forms the conductive polymer that forms the catalyst material include the monomers described above. Examples of another monomer that forms the conductive polymer include furan, pyridine, and benzene. Examples of the pyrrole derivative include 3-methylpyrrole.

  Specific examples of the redox couple include a combination of iodine anions and / or polyiodide anions.

  Furthermore, in the present invention, the conductive polymer is an electrolyte-catalyst composite electrode, wherein the conductive polymer layer contains an iodine anion and / or a polyiodide anion as a dopant.

  Examples of the conductive fibers or particles include carbon, carbon paper, and metal oxide.

  The present invention is also the electrolyte-catalyst composite electrode described in the above, wherein the electrolyte is in the form of gel, paste, clay or solid.

  The present invention further includes an electrolyte that is disposed opposite to a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and includes a chemical species that serves as a redox pair, conductive fibers or particles, and a catalyst substance. A method for producing an electrolyte-catalyst composite electrode for a dye-sensitized solar cell comprising: (a) an electrolyte containing at least a chemical species that serves as a redox pair; and conductive fibers or particles containing a catalyst substance; Manufacturing an electrolyte-catalyst composite electrode comprising the steps of: mixing a mixture into a gel, paste, clay or solid mixture; and (b) laminating the mixture on an electrode substrate to be a current collector Is the method.

The present invention further includes an electrolyte that is disposed opposite to a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and includes a chemical species that serves as a redox pair, conductive fibers or particles, and a catalyst substance. A method for producing an electrolyte-catalyst composite electrode for a dye-sensitized solar cell, comprising: (a) conductive fibers or particles that are in contact with each other or fixed to each other to be electrically connected, and comprising a catalyst substance; Forming a three-dimensional network structure on an electrode substrate serving as a current collector; and (b) filling the network structure with an electrolyte that is in the form of a gel, paste, clay, or solid. It is a manufacturing method of an electrolyte-catalyst composite electrode.

  The present invention further includes a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, an electrolyte layer containing at least a chemical species that serves as a redox pair, and an electrode disposed opposite to the semiconductor electrode. A sensitized solar cell, which is directed to a dye-sensitized solar cell that is the electrolyte-catalyst composite electrode.

  According to the present invention, as a result of intensive studies to solve the problem, an electrolyte containing a chemical species that becomes a redox pair, a conductive fiber or particle, and a conductive polymer and / or a catalyst substance are combined. As a result, even when a highly viscous electrolyte is used, the utilization factor of the catalyst is high, and the oxidized form of the oxidation-reduction pair contained in the electrolyte can be rapidly reduced.

In addition, the conductive fibers or particles are brought into contact with each other or fixed to be electrically connected to form a three-dimensional network structure, whereby the electrode characteristics can be further improved.

Furthermore, the electrode characteristics can be further improved by bringing the catalyst substance into contact with the conduction path of the oxidation-reduction pair contained on the surface of the conductive fiber or particle and contained in the electrolyte.

  Further, according to the present invention, the three-dimensional network structure in which the conductive polymer is formed on the surface of the conductive fibers or particles is brought into contact with or fixed to each other through the conductive polymer to be electrically conductive. In addition, the electrode characteristics can also be improved by supporting the catalyst substance on the surface of the conductive polymer.

  Furthermore, according to the present invention, it is possible to easily produce the electrode having excellent operability and excellent electrode characteristics with a small energy by making the electrode in which the electrolyte and the catalyst are combined as described above. Specifically, an excellent high-performance dye-sensitized solar cell can be manufactured.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a schematic cross-sectional view showing an example of the dye-sensitized solar cell of the present invention. In the dye-sensitized solar cell, a porous metal oxide semiconductor layer 4 is formed on the surface of an electrode substrate 1 comprising a transparent substrate 2 and a transparent conductive film 3 formed thereon, and the porous metal oxide is further formed. A sensitizing dye layer 5 is adsorbed on the surface of the semiconductor layer 4. And the electrolyte-catalyst composite electrode 6 of this invention is installed facing.
FIG. 2 is a schematic cross-sectional view showing an example of the electrolyte-catalyst composite electrode 6 of the present invention. The electrode base 10 functioning as a support and current collector is electrically connected to or in contact with each other. Conductive fiber or particle 7 having a three-dimensional network structure, catalyst material 8 supported on the surface of the conductive fiber or particle 7, and three-dimensional network structure of the conductive fiber or particle 7 It consists of an electrolyte 9 held in between.
FIG. 3 is a schematic cross-sectional view showing an example of the electrolyte-catalyst composite electrode 6 of the present invention. The electrode base 10 functions as a support and current collector, and a catalyst substance 8 formed on the surface thereof. Conductive fibers or particles 7 having a three-dimensional network structure in contact or fixed and electrically conducting, and an electrolyte 9 held between the three-dimensional network structures of the conductive fibers or particles 7 Become.
FIG. 4 is a schematic cross-sectional view showing an example of the electrolyte-catalyst composite electrode 6 of the present invention. The electrode base 10 functions as a support and current collector, and a conductive polymer 11 formed on the surface. Conductive fibers or particles 7 having a three-dimensional network structure that are in contact with each other or fixed and electrically connected to each other, and a catalyst material 12 supported on the conductive polymer 11, and conductive fibers or particles. 7 and an electrolyte 9 held between the three-dimensional network structure of the conductive polymer 11.
FIG. 5 is a schematic cross-sectional view showing an example of a conventional high-area catalyst electrode, in which there is an electrode substrate 13 that functions as a support and current collector, and the surface is made porous for the purpose of improving the area. Further, although a catalytic substance is supported on the surface of the electrode base 13, the catalytic substance 15 in contact with the electrolyte 14 works effectively, while the catalytic substance 16 is in contact with the electrolyte 14 because it is in the deep part of the hole. Not working effectively.

Hereinafter, a suitable form is demonstrated about each structural material of the dye-sensitized solar cell of this invention.
[Transparent substrate]
As the transparent substrate 2 constituting the electrode substrate 1, one that transmits visible light can be used, and transparent glass can be suitably used. Moreover, the thing which processed the glass surface and scattered incident light, and a translucent ground glass-like thing can also be used. Moreover, not only glass but a plastic plate, a plastic film, etc. can be used if it transmits light.
The thickness of the transparent substrate 2 is not particularly limited because it varies depending on the shape and use conditions of the solar cell. For example, when glass or plastic is used, the thickness is about 1 mm to 1 cm in consideration of durability during actual use. Yes, flexibility is required, and when a plastic film or the like is used, it is about 1 μm to 1 mm.

[Transparent conductive film]
As the transparent conductive film 3, a material that transmits visible light and has conductivity can be used, and examples of such a material include metal oxide. Although not particularly limited, for example, tin oxide doped with fluorine (hereinafter abbreviated as “FTO”), indium oxide, a mixture of tin oxide and indium oxide (hereinafter abbreviated as “ITO”), and oxidation. Zinc or the like can be suitably used. In addition, an opaque conductive material can be used as long as visible light is transmitted through a treatment such as dispersion. Such materials include carbon materials and metals. Although it does not specifically limit as a carbon material, For example, graphite (graphite), carbon black, glassy carbon, a carbon nanotube, fullerene, etc. are mentioned.
Further, the metal is not particularly limited, and examples thereof include platinum, gold, silver, ruthenium, copper, aluminum, nickel, cobalt, chromium, iron, molybdenum, titanium, tantalum, and alloys thereof. Therefore, the transparent conductive film 3 can be formed by providing a conductive material made of at least one of the above-described conductive materials on the surface of the transparent substrate 2. Alternatively, it is also possible to incorporate the conductive material into the material constituting the transparent substrate 2 and integrate the transparent substrate and the transparent conductive film into the electrode substrate 1.

As a method for forming the transparent conductive film 3 on the transparent substrate 2, in the case of forming a metal oxide, there are a sol-gel method, a vapor phase method such as sputtering and CVD, and a coating of a dispersion paste. Moreover, when using an opaque electroconductive material, the method of fixing a powder etc. with a transparent binder etc. is mentioned.
In order to integrate the transparent substrate and the transparent conductive film, the conductive film material may be mixed as a conductive filler when the transparent substrate is molded.
The thickness of the transparent conductive film 3 is not particularly limited because the conductivity varies depending on the material to be used, but is generally 0.01 μm to 5 μm, preferably 0.1 μm to 1 μm in the FTO-coated glass. It is. Further, the required conductivity varies depending on the area of the electrode to be used, and a wider electrode is required to have a lower resistance, but is generally 100Ω / □ or less, preferably 10Ω / □ or less, more preferably 5Ω. / □ or less.
The thickness of the electrode substrate 1 composed of a transparent substrate and a transparent conductive film, or the electrode substrate 1 in which the transparent substrate and the transparent conductive film are integrated varies depending on the shape and use conditions of the solar cell as described above, and thus is particularly limited. Generally, it is about 1 μm to 1 cm.

[Porous metal oxide semiconductor]
Examples of the porous metal oxide semiconductor 4 include, but are not limited to, titanium oxide, zinc oxide, tin oxide, and the like. Particularly, titanium dioxide and further anatase type titanium dioxide are preferable. Further, it is desirable that the metal oxide has few grain boundaries in order to reduce the electric resistance value. Further, in order to adsorb more sensitizing dye, the semiconductor layer is desirably porous, specifically 10 to 200 m ² / g. Further, in order to increase the light absorption amount of the sensitizing dye, it is desirable to scatter the light by making the particle diameter of the oxide to be used wide.
Such a porous metal oxide semiconductor is not particularly limited and can be provided on the transparent conductive film 3 by a known method. For example, there are a sol-gel method, dispersion paste application, electrodeposition and electrodeposition.
The thickness of such a semiconductor layer is not particularly limited because the optimum value varies depending on the oxide used, but is 0.1 μm to 50 μm, preferably 5 to 30 μm.

[Sensitizing dye]
The sensitizing dye layer 5 is not particularly limited as long as it can be excited by sunlight and can inject electrons into the metal oxide semiconductor layer 4, and a dye generally used in dye-sensitized solar cells can be used. However, in order to improve the conversion efficiency, it is desirable that the absorption spectrum overlaps with the sunlight spectrum in a wide wavelength region and the light resistance is high. Although not particularly limited, a ruthenium complex, particularly a ruthenium polypyridine complex is desirable, and a ruthenium complex represented by Ru (L) 2 (X) 2 is more desirable. Here, L is 4,4′-dicarboxy-2,2′-bipyridine, or a quaternary ammonium salt thereof, and a polypyridine-based ligand into which a carboxyl group is introduced, and X is SCN, Cl, CN It is. Examples thereof include bis (4,4′-dicarboxy-2,2′-bipyridine) diisothiocyanate ruthenium complex.
Examples of other dyes include metal complex dyes other than ruthenium, such as iron complexes and copper complexes. Further examples include organic dyes such as cyan dyes, porphyrin dyes, polyene dyes, coumarin dyes, cyanine dyes, squaric acid dyes, styryl dyes, and eosin dyes. These dyes preferably have a bonding group with the metal oxide semiconductor layer in order to improve the efficiency of electron injection into the metal oxide semiconductor layer. The linking group is not particularly limited, but a carboxyl group, a sulfonic acid group and the like are desirable.

The method for adsorbing the sensitizing dye to the porous metal oxide semiconductor 4 is not particularly limited. For example, the porous metal oxide is dissolved in a solution in which the dye is dissolved at room temperature and atmospheric pressure. A method of immersing the electrode substrate 1 on which the physical semiconductor 4 is formed may be mentioned. It is desirable that the immersion time is appropriately adjusted so that a monomolecular film of the dye is uniformly formed on the semiconductor layer depending on the type of the semiconductor, the dye, the solvent, and the concentration of the dye used. In addition, what is necessary is just to perform the immersion under a heating in order to perform adsorption | suction effectively.
Examples of the solvent used to dissolve the sensitizing dye include alcohols such as ethanol, nitrogen compounds such as acetonitrile, ketones such as acetone, ethers such as diethyl ether, halogenated aliphatic hydrocarbons such as chloroform, Examples thereof include aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as benzene, and esters such as ethyl acetate. It is desirable that the dye concentration in the solution is appropriately adjusted according to the type of dye and solvent used. For example, a concentration of 5 × 10 ⁻⁵ mol / L or more is desirable.

[Electrolyte-catalyst composite electrode to electrolyte]
The electrolyte 9 includes at least a redox pair capable of reducing the oxidized sensitizing dye and a medium for dissolving them. In the present invention, it is desirable to use a high boiling point or non-volatile solvent from a practical viewpoint. Furthermore, in order to avoid problems such as leakage of the electrolyte, it is desirable that the electrolyte has a high viscosity, and it is particularly desirable that the electrolyte be in the form of a gel, paste, clay, or solid. It is sufficient that the viscosity is high when the catalyst composite electrode is manufactured and when the solar cell is used, and the solvent raw material does not necessarily have high viscosity. Such a gelling, pasting, claying, or solidifying method is not particularly limited, and includes a method using a gelling agent such as an organic polymer, a fluorine-based polymer binder such as PVDF, and the like. A known method such as a method of using a particle or a method of mixing with particles can be used. In particular, a method of mixing and centrifuging a high-viscosity solvent and particles to form a paste can be suitably used. By using conductive particles or fibers constituting a three-dimensional network structure to be described later as the added particles, The durability can be improved by using only the essential constituent materials of the present invention. Further, after a three-dimensional network structure is configured in advance, a space in the network structure can be impregnated and retained. In addition, a lithium salt, an imidazolium salt, a quaternary ammonium salt, or the like can be added as a supporting electrolyte. Furthermore, t-butylpyridine, 1,2-dimethyl-3-propylimidazolium iodide, water, etc. are added as additives to improve the transfer rate of the redox couple and to adjust and improve various solar cell characteristics. Can be done.
The solvent as described above is not particularly limited, but can be arbitrarily selected from a non-aqueous organic solvent, water, a protic organic solvent, and the like. For example, acetonitrile, dimethylformamide, methoxyacetonitrile, methoxypropionitrile, Examples thereof include propylene carbonate. Further, as described above, from the viewpoint of improvement of durability, it is desirable that ethyl methylimidazolium bis trifluoromethane Tansuruhoni ambient temperature molten salt such as Ruimido (ionic liquid).

[Redox pair]
The oxidation-reduction pair is not particularly limited as long as it can be generally used in a battery or a solar battery. For example, a combination of a halogen diatomic molecule and a halide salt, a thiocyanate anion and Examples include a combination of two thiocyanate molecules, a polypyridyl cobalt complex, and organic redox such as hydroquinone. Among these, a combination of iodine molecules and iodide is particularly preferable.
The supporting electrolyte, the redox couple, and the like are not particularly limited because the optimum concentration differs depending on the solvent, the semiconductor electrode, the dye, and the like used, but is about 1 mmol / L to 5 mol / L. Further, the supporting electrolyte and the oxidation-reduction pair need only be contained in the electrolyte when the electrolyte-catalyst composite electrode 6 is formed, and need not be dissolved in the electrolyte solvent in advance. For example, it is possible to adopt a technique such as mixing with a constituent material having a three-dimensional network structure and then contacting and dissolving with an electrolyte solvent.

[Electrolyte-catalyst composite electrode to electrode substrate]
As illustrated in FIG. 1, the electrolyte-catalyst composite electrode 6 has a three-dimensional structure in which the surface of the electrode substrate 10 and the electrolyte 9 containing the chemical species serving as a redox pair are in contact with each other or are electrically connected to each other. The conductive fiber or particle 7 having a network structure and the catalyst material 8 are in contact with each other. At this time, the electrode substrate 10 and the conductive fibers or particles 7 are only required to be electrically connected to each other, and the presence or absence of binding is not necessarily limited.
Since the electrode substrate 10 is used as a support and current collector for a catalyst electrode, at least the surface portion and the extraction electrode portion must have conductivity.
As such a material, for example, a conductive metal or metal oxide, a carbon material, a conductive polymer, or the like is preferably used. Examples of the metal include platinum, gold, silver, ruthenium, copper, aluminum, nickel, cobalt, chromium, iron, molybdenum, titanium, tantalum, and alloys thereof. Although it does not specifically limit as a carbon material, For example, graphite (graphite), carbon black, glassy carbon, a carbon nanotube, fullerene etc. are mentioned. Moreover, when metal oxides, such as FTO, ITO, an indium oxide, and zinc oxide, are used, since it is transparent or translucent, the incident light quantity to a sensitizing dye layer can be increased, and it can use it conveniently.

  In addition, an insulator such as glass or plastic may be used as long as at least the surface of the electrode substrate is treated. As a treatment method for maintaining conductivity in such an insulator, a method of covering a part or the whole surface of the insulating material with the above-described conductive material, for example, when using a metal, plating, electrodeposition, etc. And a gas phase method such as sputtering or vacuum deposition. When a metal oxide is used, a sol-gel method or the like can be used. In addition, one or more of the above conductive material powders may be used and mixed with an insulating material.

The shape of the electrode substrate is not particularly limited because it can be changed according to the shape of the dye-sensitized solar cell used as the electrolyte-catalyst composite electrode, and may be a plate shape or a film shape that can be curved. Absent. Further, the electrode substrate may be transparent or opaque. However, it is desirable that the electrode substrate be transparent or translucent because the amount of light incident on the sensitizing dye layer can be increased and, in some cases, the design can be improved. . Generally, glass with an FTO film or a PEN film with an ITO film is used as the electrode substrate, but the conductivity is different depending on the material used, and therefore the thickness of the electrode substrate is not particularly limited. For example, in the FTO-coated glass, the thickness is 0.01 μm to 5 μm, preferably 0.1 μm to 1 μm. Further, the required conductivity varies depending on the area of the electrode to be used, and a wider electrode is required to have a lower resistance, but is generally 100Ω / □ or less, preferably 10Ω / □ or less, more preferably 5Ω. / □ or less.
The thickness of the electrode substrate 10 is not particularly limited because it varies depending on the shape and use conditions of the solar cell as described above, but is generally about 1 μm to 1 cm.

[Electrolyte-catalyst composite electrode to conductive fiber or particle, and catalyst substance]
In the electrolyte-catalyst composite electrode 6 of the present invention, the conductive fibers or particles 7 are mutually connected in order to drive a reduction reaction (hereinafter referred to as a catalytic reaction) of an oxidant of a redox pair by a catalytic substance 8 described later. In addition, it is necessary to be electrically connected to the catalyst material 8. In order to perform the catalytic reaction more efficiently, it is desirable to have a three-dimensional network structure so as to increase the surface area. At this time, the conductive fibers or particles 7 do not necessarily have to be physically bound.
In addition to electrical conduction with the conductive fibers or particles 7 as described above, the catalytic substance 8 does not proceed with the catalytic reaction unless it physically contacts the redox couple contained in the electrolyte. Accordingly, it is desirable that the catalyst material 8 is supported or at least partially coated on the surface of the conductive fibers or particles 7. Further, when the catalyst material 8 has both conductivity and catalytic performance, the electrode characteristics can be further improved by covering the conductive fibers or particles 7 as shown in FIG. 3 and bringing them into contact with each other.

  In order to improve durability, it is desirable to use high-viscosity electrolytes such as gels, pastes, clays, and solids, but unlike the case of using electrolytes with low viscosity solutions, It is difficult to fill the electrolyte up to the vicinity of the catalyst substance inside the network structure. Therefore, in the present invention, conductive fibers and particles are mixed with the electrolyte to maintain electrical conduction, and the contact area between the electrolyte 9 and the oxidation-reduction pair in the electrolyte and the catalyst substance 8 is increased. Can be improved. As a result, the catalytic substance 8 and the electrolyte 9 can be contacted even in the deep part of the network structure regardless of the capillary phenomenon, so that the catalytic substance that does not function effectively like the conventional catalyst electrode 14 illustrated in FIG. Can be greatly reduced.

  In the present invention, as a method for producing an electrolyte-catalyst composite electrode, it is desirable that the electrolyte can be integrated in a shape including an electrolyte for the purpose of improving the durability of the solar cell element and improving workability in the production process. . Therefore, it is desirable that the electrolyte, the conductive fiber or particle, and the catalyst substance are combined to form a gel, paste, clay, solid, or the like.

  As for a specific production method, for example, (a) after mixing conductive fibers or particles, a catalyst substance and an electrolyte to form a gel, paste, clay or solid, (b) the above (a) A production method in which the mixture prepared in the step is combined on an electrode substrate to be a current collector by a method such as coating or printing is desirable. At this time, in order for the conductive fibers or particles to have electrical continuity with each other, the ratio and content of each constituent material can be appropriately adjusted. Further, it is only necessary that electrical continuity is established after the step (b), and the electrical continuity may not necessarily be obtained in the mixed state of (a). Examples of such a method include a method in which a binder solution or the like is added at the time of mixing in (a) and the solvent of the binder is dried after coating on the electrode substrate in (b). Furthermore, in this manufacturing method, the electrode base body, which is a current collector / support, and the network structure made of conductive fibers or particles need only be in contact with each other and are electrically connected.・ It does not have to be fixed.

  Moreover, in the said manufacturing method, the catalyst substance needs to take electrical continuity with electroconductive fiber or particle | grains at the time of electrolyte-catalyst composite electrode formation. Therefore, rather than being mixed with other constituent materials alone in the step (a), it is mixed with the electrolyte after it is in contact with the conductive fibers or particles in advance, particularly in a state of being supported or at least partially covered. It is desirable.

  Moreover, in the said manufacturing method, the process of adding a redox pair can be performed at arbitrary time unless the characteristic of this invention is impaired. That is, in the step (a), a method of adding and mixing together with each constituent material, a method of dissolving in an electrolyte in advance, or a method of adding by mixing with an additive such as a binder or a gelling agent. There is also a method of adding and impregnating the mixture after the step (a) to dissolve it. Furthermore, a method of supporting the electrode substrate surface in advance in the step (b) and dissolving or diffusing it in the electrolyte in accordance with the application of the mixture in the step (a) may be mentioned.

In addition, in the step (a), for the method of gel, paste, clay or solid after mixing, if electrode characteristics required at the time of forming the electrolyte-catalyst composite electrode are finally obtained, There is no particular limitation, and a known technique can be used. For example, a method of using a high viscosity electrolyte, a method of adding a matrix polymer such as a fluorine polymer such as PVDF or a polyalkylene glycol material, a chemical bond such as an isocyanate group and a hydroxyl group, and a quaternary ammonium salt Examples thereof include chemical cross-linking such as a combination of polyvalent metals, and a gelling / pseudo-solidification method using a gelling agent such as polyvinylpyridine. Further, a method of adding fine particles to a high viscosity solvent such as an ionic liquid and processing it into a paste or clay by stirring or centrifuging can be suitably used. The fine particles added at this time are not particularly limited as long as they are stable in the electrolyte and do not negatively affect the solar cell characteristics, but the conductive fibers or particles that are the constituent material of the present invention are added to the particles. It is particularly preferable to use as a combination from the viewpoints of improvement in operability in the production process, improvement in durability of the solar cell, and improvement in electrode characteristics as an electrolyte-catalyst composite electrode.
In the manufacturing method, as long as it becomes a gel, paste, clay, or solid after the mixture of (a) and the electrolyte-catalyst composite electrode is used in a solar cell element, leakage of the electrolyte is prevented, The electrolyte before mixing in (a) may be a liquid having a low viscosity.

  Further, as another manufacturing method in the present invention, (c) a three-dimensional network structure in which conductive fibers or particles are brought into electrical contact with each other and are electrically connected to each other and containing a catalytic substance is collected. A step of forming the electrode substrate on the body, and (d) a method of filling the gel, paste, clay or solid electrolyte into the three-dimensional network structure produced in the step (c) Is mentioned.

  In the step (c), there is no particular limitation as to a method for forming a three-dimensional network structure on the electrode substrate in such a manner that the conductive fibers or particles are electrically connected to each other. Can take the way. For example, conductive fibers such as carbon paper, carbon cloth, and steel wool are woven, or a conductive material that retains an arbitrary shape in a bundle is used to superimpose it on the electrode substrate. .

As another method of the step (c), in the case of powdered conductive materials such as fibers and particles, there is a method of forming a three-dimensional network structure on the surface of the electrode substrate using a binder or an adhesive. . Such an adhesive is not particularly limited as long as it does not negatively affect the electrode characteristics of the obtained electrolyte-catalyst composite electrode, and a known material can be used, but a conductive material can be preferably used. When forming using a binder or an adhesive, it is necessary to secure a three-dimensional network structure. As such a method, the shape and particle size of the conductive fibers or particles used may be adjusted appropriately. And a method of constructing the network structure.
Also, insoluble particles are added to the binder or adhesive solvent, and after forming the powdery conductive material layer on the surface of the electrode substrate, the added particles are actively dissolved. A three-dimensional network structure can also be formed.

  However, when the binder or adhesive fixes and closes between the powdery conductive materials, the electrolyte is not sufficiently filled in the subsequent step (d). A similar problem occurs. Therefore, it is desirable to allow the fluid to pass through at least one direction in the layer formed of the powdered conductive material so as not to disturb the electrolyte filling after the binder or adhesive is solidified. . As another method, the layer formed of the powdery conductive material is not completely fixed, and is formed so that it can swell or flow during the filling of the electrolyte in the subsequent step (d). The method etc. are mentioned.

  That is, in the manufacturing method, the electrode base body, which is a current collector / support, and the network structure made of conductive fibers or particles are in electrical contact with each other, and in the step (d) It is sufficient that the electrolyte can be filled and a certain level of strength is maintained, and it is not necessarily required to be bound or fixed. Moreover, in this manufacturing method, the ratio and content of each constituent material can be adjusted suitably.

  In the production method, it is desirable that the catalyst material is in electrical continuity with the conductive fibers or particles and is in contact with the electrolyte when the electrolyte-catalyst composite electrode is formed. Therefore, it is desirable to form a state in contact with the conductive fibers or particles in advance, in particular, a state of supporting or at least partially covering, and then mixing with the electrolyte. As such a method, at the time of the step (c), a method of previously forming and supporting a catalytic substance on the surface of conductive fibers or particles, or between the steps (c) and (d), Examples thereof include a method of forming and supporting a catalyst substance on the surface of conductive fibers or particles having a three-dimensional network structure.

  In addition, regarding the method of making the electrolyte gel, paste, clay or solid in (d) above, in particular, if the electrode characteristics required at the time of forming the electrolyte-catalyst composite electrode can be finally obtained, A known technique can be used without limitation. For example, a method of using a high viscosity electrolyte, a method of adding a matrix polymer such as a fluorine polymer such as PVDF or a polyalkylene glycol material, a chemical bond such as an isocyanate group and a hydroxyl group, and a quaternary ammonium salt Examples thereof include chemical cross-linking such as a combination of polyvalent metals, and a gelling / pseudo-solidification method using a gelling agent such as polyvinylpyridine. Further, a method of adding fine particles to a high-viscosity solvent such as an ionic liquid and processing it into a paste or clay by stirring or centrifuging can be used.

  Moreover, in the said manufacturing method, the process of adding a redox pair can be performed at arbitrary time unless the characteristic of this invention is impaired. That is, the method of mixing or dissolving in advance in the electrolyte to be filled in the step (d) is simple and can be suitably used. Also, when the electrolyte cannot be processed into a gel, paste, clay or solid by mixing or dissolving with the electrolyte and cannot contribute to improvement in operability in production, it is used in the step (c). Examples thereof include a method of mixing or supporting with conductive fibers or particles, and dissolving or diffusing in the electrolyte filled in the step (d).

The material constituting the conductive fiber or particle 7 in the present invention is not particularly limited as long as it has high conductivity and is stable when the solar cell is driven. Examples of such materials include particulate carbon materials such as graphite, carbon black, glassy carbon, and fullerene, and fibrous carbon materials such as carbon nanotubes, and further, carbon paper and carbon cloth. Etc. have high electrical conductivity and high surface area, and can be suitably used. In addition, conductive metal oxides represented by FTO, ITO, a mixture of antimony oxide and tin oxide, zinc oxide, and the like can be preferably used. Further, the metal material has high conductivity and can be suitably used. For example, noble metals such as platinum and ruthenium and alloys thereof can be suitably used in the same manner as the current catalyst electrodes. Moreover, when not corroding by corrosive oxidation-reduction pairs, such as an iodine, the kind of metal is not specifically limited, A various metal can be utilized suitably. In particular, gold, silver, copper, and the like have high conductivity and can be suitably used. In addition, aluminum, nickel, cobalt, chromium, iron, molybdenum, titanium, tantalum, and alloys thereof have high versatility and are lower in cost than noble metals, and can be particularly preferably used.
Such conductive fibers or particles may be a single material or a mixture of one or more materials. Moreover, the shape may be a mixture of a plurality of shapes such as a fibrous shape and a particulate shape.

  The material of the catalyst substance 8 in the present invention is not particularly limited as long as the catalytic reaction can proceed, and a known material can be used. For example, noble metals and their alloys can be used. In particular, platinum and its alloys can be suitably used. As other materials, the conductive polymer is excellent in catalytic characteristics and stability, and is low in cost, so that it can be particularly suitably used.

  In the present invention, the catalytic material 8 is supported or at least partially coated on the surface of the conductive fibers or particles 7 having a three-dimensional network structure so that the catalytic substance 8 can efficiently react with the redox couple contained in the electrolyte layer. Although it is desirable to use it in a state, it is also preferable to use the catalyst material 8 itself in a porous state. Therefore, it is desirable to use a conductive polymer as a catalyst substance from the viewpoint of easy processing for increasing the surface area.

Such a conductive polymeric material may be one or more homopolymers, one or more copolymers, or a mixture of one or more homopolymers and one or more copolymers.
As a monomer for forming a conductive polymer used as the catalyst substance 8 in the present invention, an aromatic amine compound represented by the following general formula (1) or (2), a thiophene compound represented by the following general formula (3) And at least one monomer selected from the group consisting of pyrrole compounds represented by the following general formula (4).

（式（１）又は（２）中、Ｒ_１及びＲ_６はそれぞれ独立に水素原子、メチル基又はエチル基を示し、Ｒ_２〜Ｒ_５及びＲ_７〜Ｒ_１０はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、炭素原子数６〜１２のアラルキル基（例えばベンジル基）、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、アミド基、ヒドロキシル基、チオール基、カルボキシル基、スルホ基、又はホスホニウム基を示し、式（１）中、Ｒ_２とＲ_３、又はＲ_４とＲ_５はそれぞれ連結して環を形成していてもよく、式（２）中、Ｒ_８とＲ_９、又はＲ_９とＲ_１０はそれぞれ連結して環を形成していてもよい。）

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. C1-C12 alkyl group or alkoxy group, C6-C12 aryl group, C6-C12 aralkyl group (for example, benzyl group), cyano group, thiocyano group, halogen group, nitro group, amino group Group, amide group, hydroxyl group, thiol group, carboxyl group, sulfo group, or phosphonium group, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ are linked to form a ring. In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)

（式（３）中、Ｒ_１１、Ｒ_１２はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ_１１とＲ_１２は連結して環を形成していてもよい。）

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. , A nitro group, an amino group, a carboxyl group, a sulfo group, or a phosphonium group, R ₁₁ and R ₁₂ may be linked to form a ring.)

（式（４）中、Ｒ_１３、Ｒ_１４はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ_１３とＲ_１４は連結して環を形成していてもよい。）

(In Formula (4), R <_13> , R <_14> is respectively independently a hydrogen atom, a C1-C8 alkyl group or an alkoxy group, a C6-C12 aryl group, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₃ and R ₁₄ may be linked to form a ring.)

  When using the aromatic amine compound, there is no particular limitation as long as the polymer polymerized by them has catalytic performance, but even if a polymer film of a certain aromatic amine compound alone does not have catalytic performance, It is only necessary to have catalyst performance by forming a copolymer with aniline or another aromatic amine compound. The polymer constituting the conductive polymer used as the catalyst substance 8 may be a homopolymer or a copolymer, and the monomer component may be formed of one or more aromatic amine compounds to form the conductive polymer. it can.

Examples of the aromatic amine compound include aniline and aniline derivatives. More specifically, examples include aniline, anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N-methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline, and halogenated aniline. Of these, anisidine, toluidine, phenylenediamine and aniline are preferably used. Among them, aniline is particularly preferably used, and examples thereof include polymers formed by polymerizing at least aniline as a monomer. In particular, polyaniline using aniline alone as a monomer can be suitably used because of its low cost and high catalytic ability. Alternatively, a copolymer using aniline and an aromatic compound other than aniline as a monomer is also preferably used. For example, a copolymer of aniline and an aniline derivative, more specifically, aniline and anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N- Mention may be made of copolymers with comonomers selected from methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline and halogenated anilines.
When a plurality of types of aromatic amine compounds are used, their ratios are not particularly limited, but it is appropriate to polymerize the aromatic amine compounds in a molar ratio of 100 for one and 3 or more for the other. For example, when aniline and an aniline derivative are used, it is generally appropriate to polymerize the aniline and aniline derivative in a molar ratio of 100 with one being 100 and the other being 3 or more.

Examples of the thiophene compounds include thiophene and thiophene derivatives, more specifically thiophene, 3-methylthiophene, 3-butylthiophene, 3-octylthiophene, tetradecylthiophene, isothianaphthene, 3-phenylthiophene, and There are 3,4-ethylenedioxythiophene and the like. In particular, 3,4-ethylenedioxythiophene can be preferably used.
The conductive polymer layer may be formed using one or more thiophene compounds. Since the thiophene compound has a high oxidation potential, formation by electrochemical oxidative polymerization can be suitably used.

Examples of the pyrrole compound include pyrrole and pyrrole derivatives, and examples of the pyrrole derivative include those having an alkyl group having 1 to 8 carbon atoms at the 3-position. Specific examples of the pyrrole compound include pyrrole, 3-methylpyrrole, 3-butylpyrrole and 3-octylpyrrole. The conductive polymer layer may be formed using one or more pyrrole compounds.
The monomer component forming the conductive polymer is preferably one having a conductivity of 10 ⁻⁹ S / cm or more as a polymerized film.

  Further, it is desirable to add a dopant to the conductive polymer layer in order to improve conductivity. The dopant is a known material, for example, a halide anion such as hexafluoroline, hexafluoroarsenic, hexafluoroantimony, tetrafluoroboron, perchloric acid, a halogen anion such as iodine, bromine, chlorine, hexafluoroline, hexafluoroarsenic, hexa Halide anions such as fluoroantimony, tetrafluoroboron and perchloric acid, alkyl group-substituted organic sulfonate anions such as methanesulfonic acid and dodecylsulfonic acid, cyclic sulfonic acid anions such as camphorsulfonic acid, benzenesulfonic acid and paratoluenesulfone 1 to 3 sulfo groups such as acid, dodecylbenzenesulfonic acid, alkyl group-substituted or unsubstituted benzenemono- or disulfonic acid anion, 2-naphthalenesulfonic acid, 1,7-naphthalenedisulfonic acid, etc. Alkyl group-substituted or unsubstituted naphthalene sulfonate anion, anthracene sulfonic acid, anthraquinone sulfonic acid, alkyl biphenyl sulfonic acid, biphenyl disulfonic acid, etc. having an acid group, substituted or unsubstituted biphenyl sulfonic acid ion, polystyrene sulfonic acid, Polymeric sulfonate anions such as sulfonated polyether, sulfonated polyester, sulfonated polyimide, naphthalene sulfonate formalin condensate, substituted or unsubstituted aromatic sulfonate anions, bissaltylate boron, biscatecholate boron, etc. Examples thereof include boron compound anions or heteropolyacid anions such as molybdophosphoric acid, tungstophosphoric acid, and tungstomolybdophosphoric acid. These dopants may be used alone or in combination of two or more.

From the viewpoint of suppressing the desorption of the dopant, the dopant is preferably an organic acid anion rather than an inorganic anion, and it is desirable that the thermal decomposition or the like hardly occur.
In addition, by making the surface of the conductive polymer film porous, the reduction reaction of the redox couple can be efficiently performed. Therefore, among the above dopants, the polymer organic acid anion is more likely to be a dense surface. A monomolecular organic acid anion is desirable.

  The conductive polymer layer 9 is at least one selected from the group consisting of benzenesulfonic acid represented by the following general formulas (5) to (8), naphthalenesulfonic acid compounds, and salts thereof among the dopants. It is particularly desirable to contain as a dopant.

（式（５）〜（８）中、Ｒ^１〜Ｒ^２はそれぞれ独立に水素原子、炭素原子数１から１５のアルキル基、アルコキシ基、炭素原子数６〜１２のアリール基（例えばフェニル、トリル、ナフチルなど）、シアノ基、チオシアノ基、ヒドロキシル基、ハロゲン基、又はニトロ基を示し、Ｒ^１とＲ^２はそれぞれ連結して環を形成していてもよい。）
この式（５）〜（８）で表される化合物が好ましい理由について、詳細は不明であるが、これらのドーパントを用いた場合、多孔質化による物理的強度の低下を防ぎながら高電導度を達成することができるためと考察している。

(In the formulas (5) to (8), R ^{1 to} R ² are each independently a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, an alkoxy group, or an aryl group having 6 to 12 carbon atoms (for example, phenyl, tolyl). , Naphthyl, etc.), cyano group, thiocyano group, hydroxyl group, halogen group, or nitro group, and R ¹ and R ² may be linked to form a ring.
The reason why the compounds represented by the formulas (5) to (8) are preferable is not clear, but when these dopants are used, high conductivity is prevented while preventing a decrease in physical strength due to porosity. It is considered that it can be achieved.

As the dopant, iodine anions and / or polyiodide anions can also be preferably used. Although the details about this reason are unclear, the present inventors functioned as an anion contained in the conductive polymer used as the catalyst substance 8 as a dopant expressing the high conductivity of the conductive polymer. In addition, the following effects are considered. That is, in the present invention, it is required to use a high-viscosity electrolyte in order to improve durability, but the diffusion rate of the acid reduction pair is slow due to the height of the clay. In the present invention, by using conductive fibers or particles 7 to form a three-dimensional network structure, the decrease in current value is suppressed and improved as a solar cell element, but it is used as a redox pair. In the conductive polymer, the redox couple in the electrolyte and the Grothus mechanism (described in dye-sensitized solar cells for practical use, pp13, 2003, NTS Co., Ltd.) It is considered that high catalyst performance is obtained and the characteristics of the solar cell are improved because charge transfer to the electrolyte can be performed more easily.
For example, iodine anion (I ⁻ ) can be provided by using LiI, HI or the like as a dopant. The polyiodide anion is in the form of, for example, I ₃ ⁻ or I ₅ ⁻ and can be provided by dissolving and coexisting iodine (I ₂ ) and I ⁻ .

The amount of dopant used in the conductive polymer layer is not particularly limited because the optimum value varies depending on the type of dopant used, but is preferably 5 to 60% by mass, and more preferably 10 to 45% by mass.
Such a dopant can be used at an appropriate stage when the conductive polymer layer is formed. For example, it can coexist with a monomer used for forming the conductive polymer. Further, after the formation of the conductive polymer layer, it can be doped by a method such as impregnating the conductive polymer with a dopant solution.

  The conductive polymer used as the catalyst material 8 must be electrically connected to the conductive fibers or particles 7 having a three-dimensional network structure in order to advance the catalytic reaction. It is desirable to be formed on the surface of Since the conductive polymer has conductivity, it not only supports or partially covers the conductive fibers or particles 7 but also covers the entire surface of the conductive fibers or particles 7. It doesn't matter. Examples of the method for forming the conductive polymer include a method of forming a film from a solution in which the conductive polymer is dissolved. The solvent used in the solution is not particularly limited as long as it can dissolve the conductive polymer compound, and examples thereof include toluene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, butyl acetate, and particularly N-methyl-2. -Pyrrolidone can be suitably used.

  Also, a method in which a conductive polymer powder is treated in the form of a dispersion, paste or emulsion, polymer solution, or a mixture containing a binder, and then mixed with the conductive fibers or particles 7 to be supported / coated on the surface. Is also possible. Since this method is a simple process, it can be suitably used. In addition, depending on the manufacturing method as the electrolyte-catalyst composite electrode described later, there is a method of applying the conductive polymer powder and the conductive fibers or particles 7 to the electrode substrate 10 in a mixed state.

Moreover, since it is desirable that the conductive polymer used as the catalyst material 8 is in a porous state having a larger surface area, the conductive fiber or particle 7 is in contact with the solution containing the conductive polymer monomer. A method of supporting and coating the surface of the conductive fiber or particle 7 by oxidative polymerization of the monomer can be used.
As an oxidative polymerization method for the conductive polymer monomer, an electrolytic polymerization method or a chemical polymerization method which is a general polymerization method can be used. The chemical polymerization method is a method in which an oxidant is used to oxidize and polymerize a monomer that forms a conductive polymer as exemplified above (hereinafter also simply referred to as “conductive polymer monomer”). On the other hand, the electrolytic polymerization method is a method of forming a conductive polymer film on an electrode such as a metal by electrochemically oxidizing in a solution containing the conductive polymer monomer as described above.

In the case of using the above chemical polymerization method, the conductive fiber or particle is immersed in a solution containing either a conductive polymer monomer or an oxidizing agent, or after the solution is applied thereto, the other component is subsequently added. It is desirable to form a conductive polymer by immersing or coating in a solution in which the polymer is dissolved so that the polymerization proceeds on the surface of the conductive fiber or particle. The formation method by the chemical polymerization method can be preferably used because it can be carried out by a simple process. Further, it is also possible to use a method in which polymerization is carried out by immersing in a solution containing an oxidant or applying the solution and then exposing it to monomer vapor.
At this time, the shape of the conductive fibers or particles during chemical polymerization is not particularly limited. That is, as in the method for producing an electrolyte-catalyst composite electrode, a conductive polymer monomer is chemically polymerized as the catalyst substance 8 in a state where it is already applied on the electrode substrate 10 to form a three-dimensional network structure. It is also possible to form an electrolyte-catalyst composite electrode after chemically polymerizing the conductive polymer on conductive fibers or particles.

  The oxidizing agent used in the chemical polymerization method includes iodine, bromine, bromine iodide, chlorine dioxide, iodic acid, periodic acid, chlorous acid and other halides, antimony pentafluoride, phosphorus pentachloride, phosphorus pentafluoride. , Metal halides such as aluminum chloride, molybdenum chloride, permanganate, dichromate, chromic anhydride, ferric salt, cupric salt and other high-valent metal salts, sulfuric acid, nitric acid, trifluoromethanesulfuric acid Protonic acids such as oxygen compounds such as sulfur trioxide and nitrogen dioxide, hydrogen peroxide, ammonium persulfate, peroxo acids such as sodium perborate or salts thereof, or molybdophosphoric acid, tungstophosphoric acid, tungstomolybdophosphoric acid There are known substances such as heteropolyacids or salts thereof, and at least one of them can be used.

  On the other hand, the electropolymerization method can obtain a conductive polymer having a relatively high conductivity, and the synthesis method thereof is simple, and therefore can be suitably used as a method for producing an electrode material. When electrolytic polymerization is used in the present invention, the electrode base 10 in a state in which conductive fibers or particles form a three-dimensional network structure is used as an electrode, and electrolytic oxidation is performed in an electrolytic solution in which a conductive polymer monomer is dissolved. Can be done.

  The electropolymerization solvent used in the electropolymerization method is not particularly limited as long as it can dissolve the conductive polymer monomer and is stable even in the electropolymerization potential of the conductive polymer monomer. For example, water, acetonitrile, etc. Nitriles, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, carbonates such as propylene carbonate, tetrahydrofuran and the like can be used. These may be used alone or as a mixed solvent of two or more. Of the above, organic solvents having a certain degree of polarity, such as acetonitrile, methanol, propylene carbonate, tetrahydrofuran and the like, can be suitably used. Furthermore, when adding the said dopant, it is desirable that a dopant can also be melt | dissolved.

As electrolytic polymerization conditions, an electrode substrate having a surface formed with a three-dimensional network structure composed of conductive fibers or particles is immersed in an electrolytic polymerization solution in which the conductive polymer monomer is dissolved in advance, and the same electrolytic solution is used. Polymerization proceeds by applying an arbitrary voltage between the counter electrode and the counter electrode. The conductive polymer monomer concentration at this time is not particularly limited because the optimum value varies depending on the type of the conductive polymer monomer, but generally a range of 0.01 mol / L to 10 mol / L is appropriate. A range of 0.05 to 3 mol / L is often used. In the case of coexisting a dopant, the concentration of the dopant is suitably in the range of 1/10 to 100 times the conductive polymer monomer concentration, and often in the range of 1/3 to 20 times. . The applied current density at the time of polymerization is not particularly limited because the optimum value varies depending on the type of the conductive polymer monomer, the conductive fibers or particles 7 to be used, and the surface area thereof, but is 0.01 mA / cm. a range of ² to 1A / cm ² is suitably in the range of often 1mA / cm ² ~100mA / cm ² is used.

[Electrolyte-catalyst composite electrode in which three-dimensional network structures are contacted or fixed to each other via a conductive polymer layer formed on the surface]
As an example of the electrolyte-catalyst composite electrode in the present invention, as shown in FIG. 4, conductive fibers or particles 7 having a three-dimensional network structure are interposed through a conductive polymer 11 formed on the surface. For example, a structure in which the conductive material 11 is supported by the conductive polymer 11 that are electrically connected to each other or are electrically connected to each other is exemplified.
As described above, it is desirable to use a high boiling point or non-volatile solvent from a practical viewpoint. Furthermore, in order to avoid problems such as leakage of the electrolyte, it is desirable that the electrolyte has a high viscosity, and it is particularly desirable that the electrolyte be in the form of a gel, paste, clay, or solid. However, in such an electrolyte, unlike the case of using an electrolyte of a solution having a low viscosity, it is difficult to fill the electrolyte up to the vicinity of the catalyst substance inside the network structure by capillary action.

  Therefore, in the present invention, electrically conductive fibers and particles are mixed with the electrolyte, thereby maintaining electrical conduction and greatly improving the contact area between the electrolyte 9 and the redox couple in the electrolyte and the catalyst substance. it can. At this time, if the surface of the conductive fiber or particle 7 is coated with the conductive polymer 11, the surface area can be further increased than that directly supported by the fiber or particle while maintaining current flow. Available to: At this time, the conductive polymer 11 is preferably formed in a more porous state. As a result, even when a part of the catalyst material 12 is formed inside the conductive polymer layer, the electrolyte 9 is easily filled into the porous conductive polymer 11, so that the electrode characteristics and catalyst can be reduced. A further improvement appears in the effective utilization rate of substances.

  The material of the catalyst substance 12 at this time is not particularly limited as long as the catalytic reaction can proceed, and a known material can be used. For example, noble metals and their alloys can be used. In particular, platinum and its alloys can be suitably used. Further, as other materials, the conductive polymer can be used particularly preferably because it can be formed at low cost with excellent catalytic characteristics and stability, and also excellent adhesion to the conductive polymer 11 serving as a carrier.

The conductive polymer 11 is essential to have conductivity, but may not function directly as a catalyst. The monomer that forms the polymer of the conductive polymer 11 may be the same as or different from the monomer that forms the polymer of the conductive polymer that can be used as the catalyst material 8 described above. In addition, the polymer of the conductive polymer 11 may be a homopolymer formed from a single monomer or a mixture thereof, a copolymer composed of two or more monomers, or a mixture thereof. It may be a mixture of a homopolymer and a copolymer.
That is, the conductive polymer 11 can include one or more homopolymers, one or more copolymers, or a mixture of one or more homopolymers and one or more copolymers. 11 and the polymer of the conductive polymer that can be used as the catalyst material can include the same or different polymers.
In forming the conductive polymer 11, the constituent components, formation method, and conditions may generally conform to the materials and conditions described for the conductive polymer used as the catalyst substance 8 described above.
For example, electropolymerization of the conductive polymer 11 is performed using the electrode substrate 10 as an electrode in a solution in which the conductive fibers or particles 7, the monomer of the conductive polymer, and, if necessary, the electrolyte are dissolved and dispersed. For example, a conductive fiber or particle 7 dispersed in an electrolytic solution can be taken into the conductive polymer 11 or electrodeposited.

In the present invention, the main conduction path for driving the catalytic reaction is carried by the conductive fibers or particles 7, and the conductive polymer 11 is brought into contact with and bonded to each other, and A porous material is desirable for functioning as a support for the catalyst material 12. Accordingly, the thickness of the conductive polymer 11 is not particularly limited, but if the conductive polymer 11 is too thick, the electrical resistance value increases, and the conductive fiber 11 swells due to electrolyte swelling. Or it is desirable to change suitably according to the formation conditions of the particle | grains 7 and electrolyte-catalyst composite electrode. The thickness of the conductive polymer layer 11 is generally about 5 nm to 5 mm, preferably 100 μm or less.
The specific surface area of the conductive polymer 11 is not particularly limited since the optimum value varies depending on the monomer used, usually at 0.1 m ² / g or more N ₂ BET specific surface area, more preferably 5 m ² / g or more is suitable, and more preferably 10 m ² / g or more.

  Thus, an electrolyte comprising conductive fibers or particles having a three-dimensional network structure that are in contact with each other or fixed and electrically connected to each other, and a catalyst substance, and combined with the electrode substrate 10 as a current collector / support -A catalyst composite electrode is obtained, or a three-dimensional network structure is brought into electrical contact with each other via a conductive polymer layer formed on the surface, and is electrically connected; An electrolyte-catalyst composite electrode formed on the surface of the molecular layer and combined with the electrode substrate 10 as a current collector / support is obtained.

  After preparing each component material of the dye-sensitized solar cell as described above, it is assembled so that the metal oxide semiconductor electrode and the electrolyte-catalyst composite electrode face each other by a conventionally known method. Complete the solar cell.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited at all by these.
[Example 1]
[Porous metal oxide semiconductor]
As a transparent base with a transparent conductive film, glass with FTO coating (25 mm × 50 mm made by Japanese plate glass) was used, and a titanium dioxide paste (Ti-Nanoxide T made by Soralonix) was applied to the surface with a bar coater, and dried at 450 ° C. After baking for 30 minutes and leaving as it is at room temperature, a porous titanium oxide semiconductor electrode having a thickness of 10 μm was formed.

[Adsorption of sensitizing dye]
As a sensitizing dye, a bis (4,4′-dicarboxy-2,2′-bipyridine) diisothiocyanate ruthenium complex generally called N3dye was used. The porous titanium oxide semiconductor electrode once heated to 150 ° C. was immersed in an ethanol solution having a pigment concentration of 0.5 mmol / L, and left standing under light shielding overnight. Thereafter, excess pigment was washed with ethanol and then air-dried to produce a semiconductor electrode of a solar cell. Further, the semiconductor layer was ground so that the obtained semiconductor electrode had a titanium oxide projected area of 25 mm ² .

[Production of electrolyte-catalyst composite electrode]
As an electrode substrate with a conductive film layer, FTO-coated glass (Nippon Sheet Glass 25 mm × 50 mm) was used and ultrasonically cleaned in an organic solvent. The FTO-coated glass is immersed in an aqueous solution containing 0.1 mol / L aniline and 1 mol / L hydrochloric acid in a state where carbon paper (TGP-H-030 manufactured by Toray Industries, Inc.) is brought into contact with the glass. The polyaniline film is formed on the FTO-coated glass surface and the carbon paper surface by electrochemically oxidizing aniline using the carbon paper through the attached glass as an electrode, and then washed with pure water and then at 100 ° C. in air. And dried.
Prepared as electrolyte with 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide in which ethylmethylimidazolium iodide and lithium iodide as iodine-reduction pair and iodine, and 1-methylbenzimidazole as additive were dissolved Then, an electrolyte-catalyst composite electrode was obtained by filling the carbon paper with polyaniline / glass with FTO film.

[Assembly of solar cells]
The semiconductor electrode produced as described above and the electrolyte-catalyst composite electrode were placed so as to face each other.

[Measurement of photoelectric conversion characteristics of solar cells]
The above solar cell is irradiated with pseudo-sunlight with an amount of light of 100 mW / cm ² to provide an open circuit voltage (hereinafter abbreviated as “Voc”), a short-circuit current density (hereinafter abbreviated as “Jsc”), and a shape. When the factors (hereinafter abbreviated as “FF”) and photoelectric conversion efficiency were evaluated, the following results were obtained.
About each measured value of "Voc", "Jsc", "FF", and a photoelectric conversion efficiency, it represents that a larger value is preferable as a performance of a photovoltaic cell.

[Measurement results of Example 1]
Open circuit voltage (Voc): 0.67V
Short circuit current density (Jsc): 14.6 mA / cm ²
Form factor (FF): 0.64
Photoelectric conversion efficiency: 6.2%

[Example 2]
N-Butanol in which 3,4-ethylenedioxythiophene 0.05 mol / L and imidazole 0.02 mol / L and p-toluenesulfonic acid iron (III) salt 0.1 mol / L as an oxidizing agent were dissolved In a 2-propanol mixed solution, Ketjen Black [trade name Ketjen Black EC600JD (hereinafter abbreviated as Ketjen Black)] manufactured by Lion Co., Ltd. is dispersed, and further dispersed evenly with ultrasonic treatment. And dried to obtain a powder. The obtained powder was heated to 110 ° C. to polymerize ethylenedioxythiophene adsorbed on the surface of the ketjen black to obtain ketjen black carrying polyethylenedioxythiophene (hereinafter abbreviated as PEDOT). The obtained PEDOT-supported ketjen black was kneaded and centrifuged with an electrolyte to obtain a paste. The obtained paste was applied on FTO-coated glass to complete an electrolyte-catalyst composite electrode. The electrolyte composition, solar cell assembly method and evaluation method were the same as in Example 1.
[Measurement results of Example 2]
Open circuit voltage (Voc): 0.75V
Short circuit current density (Jsc): 15.1 mA / cm ²
Form factor (FF): 0.60
Photoelectric conversion efficiency: 6.8%

Example 3
By immersing FTO-coated glass in an aqueous solution containing 0.1 mol / L of pyrrole in which Ketjen black is dispersed and 0.1 mol / L of sodium p-toluenesulfonate, and oxidizing pyrrole electrochemically, Polypyrrole and ketjen black were electrodeposited on the glass surface with FTO coating. The obtained FTO-coated glass with a polypyrrole / ketjen black mixed layer was once washed with pure water, and then, using the FTO-coated glass as an electrode, 0.5 mol / L of sulfuric acid and 5 mmol / L of H ₂ PtCl ₆ were included. Electrolytic reduction was performed in an aqueous solution, and platinum was reduced and deposited on the electrode surface. Then, after passing through pure water, a washing | cleaning, and a drying process, electrolyte was filled and the electrolyte-catalyst composite electrode was obtained. The electrolyte was used after adding polyvinylpyrrolidone to the electrolyte composition of Example 1 and thickening it into a paste. The solar cell assembly method and evaluation method were the same as in Example 1.
[Measurement results of Example 3]
Open-circuit voltage (Voc): 0.72V
Short circuit current density (Jsc): 14.9 mA / cm ²
Form factor (FF): 0.69
Photoelectric conversion efficiency: 7.4%

Example 4
CI Kasei Co., Ltd. and manufactured by ITO nanoparticles (trade name NanoTek), Kureha Chemical Industry Co., Ltd. polyvinylidene fluoride resin (PVDF) solution After (trade name Kureha KF polymer) was kneaded by processing the clayey After applying and adhering onto the glass with FTO coating, it was dried in air at 120 ° C. Further, in the aqueous solution in which the monomer is 3,4-ethylenedioxythiophene 0.05 mol / L and p-toluenesulfonic acid 0.1 mol / L and lithium iodide 0.1 mol / L are dissolved as the dopant, the ITO layer is attached. Using the glass with FTO film as an electrode, ethylenedioxythiophene was electrochemically oxidized to coat the surface of the glass with FTO film with ITO layer with PEDOT. The electrolyte composition, solar cell assembly method and evaluation method were the same as in Example 3.
[Measurement results of Example 4]
Open circuit voltage (Voc): 0.62V
Short circuit current density (Jsc): 14.2 mA / cm ²
Form factor (FF): 0.68
Photoelectric conversion efficiency: 6.0%

Example 5
Ammonium persulfate was dropped into an ice bathed sulfuric acid aqueous solution having an aniline concentration of 0.1 mol / l to polymerize aniline to obtain polyaniline particles. Ammonia water was allowed to act on the obtained polyaniline particles and then dissolved in N-methylpyrrolidone (hereinafter abbreviated as NMP) so that the polyaniline was 4% by mass to obtain a polyaniline NMP solution in an emeraldine base state.
Ketjen black was added to the polyaniline NMP solution and ultrasonically dispersed, and then heated and concentrated, and 2,7-naphthalenedisulfonic acid was further added and stirred to gel. The obtained gel was mixed with an electrolyte, and then applied to an FTO-coated glass and dried to obtain an electrolyte-catalyst composite electrode. In addition, about the assembly method and evaluation method of the photovoltaic cell, it carried out similarly to Example 1. FIG.
[Measurement results of Example 5]
Open circuit voltage (Voc): 0.64V
Short circuit current density (Jsc): 13.9 mA / cm ²
Form factor (FF): 0.60
Photoelectric conversion efficiency: 5.3%

Example 6
Stainless steel wool (manufactured by Nippon Steel Wool Co., Ltd.) is immersed in an ice bathed aqueous solution containing 0.1 mol / L of pyrrole and 0.1 mol / L of sodium 2,7-anthraquinone disulfonate. The surface was coated with polypyrrole by electrochemically oxidizing pyrrole using as an electrode, washed with pure water, and dried in air at 100 ° C. The obtained polypyrrole-coated stainless wool was impregnated with the same polyaniline NMP solution as that prepared in Example 5, and was pulled up and dried in air at 120 ° C. The obtained polyaniline / polypyrrole-coated steel wool was impregnated with an aqueous hydrochloric acid solution, and polyaniline was doped with hydrochloric acid to obtain an emeraldine salt state to impart conductivity. The obtained coated steel wool was washed with pure water, dried in air at 100 ° C., and filled with an electrolyte to obtain an electrolyte-catalyst composite electrode. The electrolyte composition, solar cell assembly method and evaluation method were the same as in Example 3.
[Measurement results of Example 6]
Open-circuit voltage (Voc): 0.66V
Short circuit current density (Jsc): 13.6 mA / cm ²
Form factor (FF): 0.65
Photoelectric conversion efficiency: 5.8%

[Comparative Example]
The semiconductor electrode was produced in the same manner as in Example 1. Instead of the electrolyte-catalyst composite electrode, a platinum electrode was used as the catalyst electrode. In the catalyst electrode, FTO glass was used for the electrode substrate, and a platinum layer was formed on the FTO glass by a sputtering method. The thickness of the platinum layer was about 150 nm. The semiconductor electrode and the catalyst electrode were placed so as to face each other, and the electrolyte was impregnated between both electrodes by capillary action. The electrolyte was prepared in the same manner as in Example 1.
[Measurement results of Comparative Example 1]
Open circuit voltage (Voc): 0.67V
Short-circuit current density (Jsc): 10.2 mA / cm ²
Form factor (FF): 0.64
Photoelectric conversion efficiency: 4.4%

  Table 1 below shows the measured values of conductive materials, catalyst substances, and solar cell characteristics that form the three-dimensional network structure of each of the above examples. The parentheses in the material column represent the dopant.

  From the above results, it can be seen that the dye-sensitized solar cell provided with the catalyst electrode of the present invention has excellent photoelectric conversion efficiency.

According to the present invention, even when a high-viscosity electrolyte is used, it can be produced with an inexpensive material and a simple manufacturing method, and the utilization rate of the catalyst is high, and the oxidant of the redox couple contained in the electrolyte can be quickly obtained. An electrolyte-catalyst composite electrode excellent in durability that can be reduced to a low temperature is provided. Furthermore, when manufacturing an electrolyte-catalyst composite electrode of a dye-sensitized solar cell, a method for manufacturing the electrode excellent in electrode characteristics with a low energy and easily with good operability is provided.
Furthermore, according to the present invention, a dye-sensitized solar cell having excellent photoelectric conversion efficiency is provided by disposing the electrolyte-catalyst composite electrode opposite to a semiconductor electrode containing a dye having a photosensitizing action. Can do.

It is a cross-sectional schematic diagram which shows an example of a structure of the dye-sensitized solar cell of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the electrolyte-catalyst composite electrode of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the electrolyte-catalyst composite electrode of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the electrolyte-catalyst composite electrode of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the conventional catalyst electrode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode base body 2 Transparent base body 3 Transparent electrically conductive film 4 Porous metal oxide semiconductor layer 5 Sensitizing dye layer 6 Electrolyte-catalyst composite electrode 7 Conductive fiber or particle 8 Catalytic substance 9 Electrolyte 10 Electrode base body 11 Conductive polymer layer 12 Catalyst Material 13 Electrode Base 14 Electrolyte 15 Effective Catalyst Material 16 Invalid Catalyst Material 17 Porous Conductive Layer

Claims (14)

An electrode placed opposite to a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, and electrically connected to or in contact with an electrolyte containing a chemical species and an ionic liquid as a redox pair And composed of conductive fibers or particles having a three-dimensional network structure , a conductive polymer and a catalyst material, and the catalyst material is supported on the surface of the conductive fibers or particles and contained in the electrolyte. An electrolyte-catalyst composite electrode for a dye-sensitized solar cell, wherein the electrolyte-catalyst electrode is in contact with a conduction path of a redox couple. Catalyst material in conductive fibers or particle surface a three-dimensional network structure is formed by carrying, in claim 1, characterized in that electrically conductive been contacted or adhered to each other via the catalytic material The electrolyte-catalyst composite electrode described. The electrolyte-catalyst composite electrode according to claim 1 or 2, wherein the catalyst substance is a conductive polymer. The conductive polymer is an aromatic amine compound represented by the following general formula (1) or (2), a thiophene compound represented by the following general formula (3), a pyrrole compound represented by the following general formula (4) The electrolyte-catalyst composite electrode according to claim 3 , which is a polymer formed by polymerizing at least one monomer selected from the group consisting of:

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. An alkyl group or an alkoxy group having 1 to 8 atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, a halogen group, a nitro group, an amino group, an amide group, A hydroxyl group, a thiol group, a carboxyl group, a sulfo group, or a phosphonium group is shown, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ may be linked to form a ring, In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. , A nitro group, an amino group, a carboxyl group, a sulfo group, or a phosphonium group, R ₁₁ and R ₁₂ may be linked to form a ring.)

(In Formula (4), R <_13> , R <_14> is respectively independently a hydrogen atom, a C1-C8 alkyl group or an alkoxy group, a C6-C12 aryl group, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₃ and R ₁₄ may be linked to form a ring.) The electrolyte-catalyst composite electrode according to claim 3 , wherein the conductive polymer is a polymer formed by polymerizing at least aniline as a monomer. The electrolyte-catalyst composite electrode according to claim 3 , wherein the conductive polymer is a polymer formed by polymerizing at least a thiophene compound represented by the general formula (3) as a monomer. The electrolyte-catalyst composite electrode according to claim 6 , wherein the conductive polymer is a polymer formed by polymerizing at least 3,4-ethylenedioxythiophene as a monomer. The electrolyte-catalyst composite electrode according to claim 3 , wherein the conductive polymer is a polymer formed by polymerizing at least a pyrrole compound represented by the general formula (4) as a monomer. The electrolyte-catalyst composite electrode according to any one of claims 3 to 8 , wherein the conductive polymer contains an iodine anion and / or a polyiodide anion as a dopant. Conductive fibers or particles, carbon, carbon paper, metal oxides, and are selected from metal, to any one of claims 1-9, characterized in that it is formed from at least one conductive material The electrolyte-catalyst composite electrode described. The electrolyte-catalyst composite electrode according to any one of claims 1 to 10 , comprising an iodine anion and / or a polyiodide anion as a redox pair. The electrolyte-catalyst composite electrode according to any one of claims 1 to 11 , wherein the electrolyte is in the form of a gel, a paste, a clay, or a solid.   Dye sensitization comprising an electrolyte containing a chemical species to be a redox couple, a conductive fiber or particle, and a catalyst substance that are disposed opposite to a light-transmitting semiconductor electrode containing a dye having a photosensitizing action A method for producing an electrolyte-catalyst composite electrode for a solar cell, wherein (a) electrically conductive fibers or particles are brought into contact with each other or adhered to each other to be electrically connected, and a three-dimensional network structure comprising a catalyst substance An electrolyte-catalyst composite electrode comprising: (b) forming a gel, paste, clay, or solid electrolyte in the network structure; Manufacturing method. A dye-sensitized solar cell having at least a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, an electrolyte layer containing at least a chemical species serving as a redox pair, and an electrode arranged to face the semiconductor electrode A dye-sensitized solar cell, wherein the electrode is the electrolyte-catalyst composite electrode according to any one of claims 1 to 12 .

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